usr/src/lib/libc/port/rt/shm.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include "lint.h"
  30 #include <sys/types.h>
  31 #include <sys/mman.h>
  32 #include <fcntl.h>
  33 #include <limits.h>
  34 #include <errno.h>
  35 #include "pos4obj.h"
  36
  37 int
  38 shm_open(const char *path, int oflag, mode_t mode)
  39 {
  40         int crflag;
  41         int fd;
  42         int flags;
  43
  44         if (__pos4obj_check(path) == -1)
  45                 return (-1);
  46
  47         /* acquire semaphore lock to have atomic operation */
  48         if (__pos4obj_lock(path, SHM_LOCK_TYPE) < 0)
  49                 return (-1);
  50
  51         fd = __pos4obj_open(path, SHM_DATA_TYPE, oflag, mode, &crflag);
  52
  53         if (fd < 0) {
  54                 (void) __pos4obj_unlock(path, SHM_LOCK_TYPE);
  55                 return (-1);
  56         }
  57
  58         if ((flags = fcntl(fd, F_GETFD)) < 0 ||
  59             fcntl(fd, F_SETFD, flags | FD_CLOEXEC) < 0) {
  60                 (void) __pos4obj_unlock(path, SHM_LOCK_TYPE);
  61                 (void) __close_nc(fd);
  62                 return (-1);
  63         }
  64
  65         /* relase semaphore lock operation */
  66         if (__pos4obj_unlock(path, SHM_LOCK_TYPE) < 0) {
  67                 (void) __close_nc(fd);
  68                 return (-1);
  69         }
  70
  71         return (fd);
  72 }
  73
  74 int
  75 shm_unlink(const char *path)
  76 {
  77         int     oerrno;
  78         int     err;
  79
  80         if (__pos4obj_check(path) < 0)
  81                 return (-1);
  82
  83         if (__pos4obj_lock(path, SHM_LOCK_TYPE) < 0)
  84                 return (-1);
  85
  86         err = __pos4obj_unlink(path, SHM_DATA_TYPE);
  87
  88         oerrno = errno;
  89
  90         (void) __pos4obj_unlock(path, SHM_LOCK_TYPE);
  91
  92         errno = oerrno;
  93         return (err);
  94
  95 }